Electromagnetic flexure

Patent, 2015

An electromagnetic valve comprises a yoke (10); a magnet (30a, 30b) having pole pieces (50a, 50b) defining a gap; a flexure assembly (40) having one end attached to the yoke, such that part of the flexure assembly extends into the gap, the flexure assembly having at least one resilient portion formed of a resilient material and at least one magnetisable portion, wherein that part of the flexure assembly that extends into the gap is movable between the pole pieces through an intermediate position towards which it is resiliently biased such that a resilient mechanical force is generated by deflecting the resilient portion from an undetected position; and means (20) for polarising the magnetisable portion of the flexure assembly so that the part of the flexure assembly that is movable between the pole pieces is attracted towards a pole piece by a magnetic force, thereby defining a valve state; wherein the magnetisable portion and the resilient portion of the flexure assembly are configured such that the magnetic force defining the valve state is greater than the resilient mechanical force.